The map of the value stream is a diagram where are included all the necessary steps to cover by the information flow and materials from the receiving of a control to the productâs delivery. Lining (tracing) the value stream map can be a repetitious process but can also be a requirement (necessary condition) for improvement. Within the framework of this article one will make a description of this instrument of Lean Manufacturing system, of the stages necessary to its accomplishment and one will emphasize the information that can be obtained after its accomplishment.